Providing Environmental Enrichment without Altering Behavior in Male and Female Wistar Rats ().

In research using animal models, subjects are commonly maintained under standard housing conditions, mainly because of the idea that enhancing welfare conditions could alter experimental data. Another common practice in many laboratories relates to the preponderant use of males. Several reasons justifying this practice include the rapid hormonal and endocrine change in females, which may require a higher number of female animals to achieve more homogenous groups, thereby creating a dilemma with the reduction principle in animal research.